Phosphorus vs Iron - The Planted Tank Forum
 20Likes
  • 2 Post By Seattle_Aquarist
  • 1 Post By natemcnutty
  • 1 Post By marks_01
  • 3 Post By natemcnutty
  • 5 Post By burr740
  • 1 Post By 64D-1701
  • 2 Post By Deanna
  • 3 Post By burr740
  • 2 Post By Deanna
 
LinkBack Thread Tools Display Modes
post #1 of 12 (permalink) Old 02-12-2019, 01:21 AM Thread Starter
Planted Tank Guru
 
Seattle_Aquarist's Avatar
 
PTrader: (64/100%)
Join Date: Jun 2008
Location: Seattle, WA
Posts: 6,291
Phosphorus vs Iron

Hi All,

For the last year or so I have been dealing with interveinal chlorosis on the new leaves of my Microsporum pteropus (java fern) (both 'Windelow' and 'Trident') in one of my tanks. A month ago I did a 'tear-down' of the tank, cleaned everything, added in some of the old plants and some new species. (See Roy's 30G Planted 'Old Skool' Bay of Bengal Biotope) Unfortunately the new leaves of the java ferns continue to exhibit the same interveinal chlorosis (see below).



Since I sent up the tank I have been taking regular readings of nutrients, pH, dKH, dGH, and nitrates. Today the readings are on my 30 gallon (24 gallons water volume):
pH - 6.4 (7.2 de-gassed)
dKH - 5.0
dGH - 9.0
Ammonia - 0
Nitrites - 0
Nitrates (ppm of NO3) - 10 ppm (double dosed KNO3 today to increase to 20 ppm where I try to keep it)
Phosphate - 5.0
Iron - 0.05 ppm (tomorrow is an iron dosing day)


I dose KNO3, K2SO4, KH2PO4, CSM+B (0.29 ppm 2X per week), ferrous gluconate (0.100 2X per week), and for my 2.0 dKH / 2.0 dGH water CaSO4 and MgSO4.

I spent some time today reading up on the adversarial effects phosphate has on the iron uptake and vice-versa. In other words excess phosphorus adversely effects the uptake of iron and excess iron adversely effects the uptake of phosphorus. I thought possibly I would try an experiment. I will keep dosing my iron as indicated above but lower my phosphate level to 2.0 or lower and see what effect it has on the interveinal chlorosis as the new leaves emerge. To speed this process I am increasing my Mg dosing by 1.0 ppm 2X per week since increased Mg increases the uptake of P. I will stop the extra Mg once the P has reached 2.0

What are you thoughts / experience on this 'experiment'?
Greggz and KZB like this.

Roy_________
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

75 Gallon, 2X55W AH Supply CF 8800K, 1XFluval F&P 2.0; 45 Gallon Tall, 96Watt AH Supply CF 6700K; 30 Gallon Long; Fluval F&P 2.0; 20 Gallon, 1X26W AH Supply LED; all with CO2 and (Calcined) Montmorillonite Clay

Last edited by Seattle_Aquarist; 02-12-2019 at 02:53 AM. Reason: added Fe reading
Seattle_Aquarist is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 02-12-2019, 02:04 AM
Planted Tank Guru
 
natemcnutty's Avatar
 
PTrader: (8/100%)
Join Date: May 2016
Location: Portland, OR
Posts: 2,367
Roy, I'm curious to see your results. I've been having similar issues with S. repens. Adding significantly more Mg has really helped most species in my tank, but the issue with the S. repens still persists.

I'm at 25N/5P/18K currently with 15/7 Ca/Mg. I just cut extra K2SO4, but I'd be willing to test out less P in a month or so once the plants have fully responded to my recent changes (Joe convinced me to give it a try)
Seattle_Aquarist likes this.
natemcnutty is offline  
post #3 of 12 (permalink) Old 02-12-2019, 02:21 AM Thread Starter
Planted Tank Guru
 
Seattle_Aquarist's Avatar
 
PTrader: (64/100%)
Join Date: Jun 2008
Location: Seattle, WA
Posts: 6,291
Quote:
Originally Posted by natemcnutty View Post
Roy, I'm curious to see your results. I've been having similar issues with S. repens. Adding significantly more Mg has really helped most species in my tank, but the issue with the S. repens still persists.

I'm at 25N/5P/18K currently with 15/7 Ca/Mg. I just cut extra K2SO4, but I'd be willing to test out less P in a month or so once the plants have fully responded to my recent changes (Joe convinced me to give it a try)
Hi @natemcnutty,

K2SO4 is my second choice to try, please let me know your results of cutting back K.

Roy_________
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

75 Gallon, 2X55W AH Supply CF 8800K, 1XFluval F&P 2.0; 45 Gallon Tall, 96Watt AH Supply CF 6700K; 30 Gallon Long; Fluval F&P 2.0; 20 Gallon, 1X26W AH Supply LED; all with CO2 and (Calcined) Montmorillonite Clay
Seattle_Aquarist is offline  
 
post #4 of 12 (permalink) Old 02-12-2019, 02:29 AM
Algae Grower
 
PTrader: (0/0%)
Join Date: Jan 2017
Location: South New Jersey, USA
Posts: 60
@Roy, it sounds like you're on the right track. Reduce that P and let us know how it goes.
@natemcnutty, notice that your P is also 5 like @Roy's. Sounds like you have the same issue.
Seattle_Aquarist likes this.
marks_01 is offline  
post #5 of 12 (permalink) Old 02-12-2019, 04:20 AM
Planted Tank Guru
 
natemcnutty's Avatar
 
PTrader: (8/100%)
Join Date: May 2016
Location: Portland, OR
Posts: 2,367
Quote:
Originally Posted by marks_01 View Post
@natemcnutty, notice that your P is also 5 like @Roy's.
I feel this is probably a case of "correlation does not imply causation"

Mulder's chart is really helpful in understanding how, in general, nutrients interact with one another. Increased P levels actually requires increased Mg levels. I'm pushing 40ppm CO2 with over 100 PAR at substrate at peak and was blowing through 20N/2P that I was dosing previously, so I needed to increase P but never increased Mg.

Reducing P like Roy is looking at will not only help make more Fe available, it will also make more K available which drives up the demand for Fe. Changing one thing can affect many others

We are keeping plants in the same tank that are from completely different origins/regions and water parameters, and we try to strike a balance that keeps most everything healthy. There will always be times where changes make some plants happy while making others unhappy.
Greggz, Seattle_Aquarist and KZB like this.
natemcnutty is offline  
post #6 of 12 (permalink) Old 02-12-2019, 04:58 AM
Planted Tanker
 
burr740's Avatar
 
PTrader: (122/100%)
Join Date: Feb 2014
Location: Bama
Posts: 5,451
In addition to Fe and P competing for uptake by the plants, another big thing is if Fe doesnt have a strong enough chelate, relative to PH, the unbound Fe will quickly bind with PO4 rendering both unavailable to plants (FePO4)


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




burr740 is online now  
post #7 of 12 (permalink) Old 02-12-2019, 12:58 PM
Wannabe Guru
 
Edward's Avatar
 
PTrader: (0/0%)
Join Date: Apr 2005
Location: at home
Posts: 1,055
Quote:
Originally Posted by Seattle_Aquarist View Post
I will keep dosing my iron as indicated above but lower my phosphate level to 2.0 or lower and see what effect it has on the interveinal chlorosis as the new leaves emerge. To speed this process I am increasing my Mg dosing by 1.0 ppm 2X per week since increased Mg increases the uptake of P. I will stop the extra Mg once the P has reached 2.0
Increasing Mg dosing by 1 ppm from what base? You don’t say what is there now.

I would try dosing PO4 to maintain 0.1 ppm + fish waste in the water column and not changing anything else, especially with this plant it can take 6 months or more to fully adjust to the new conditions.

Perpetual Preservation System
The most accurate Aquatic plant fertilizers


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by Edward; 02-12-2019 at 01:40 PM. Reason: .
Edward is online now  
post #8 of 12 (permalink) Old 02-12-2019, 01:32 PM
Algae Grower
 
64D-1701's Avatar
 
PTrader: (0/0%)
Join Date: Apr 2018
Location: Dallas, TX
Posts: 101
Quote:
Originally Posted by Seattle_Aquarist View Post
I dose KNO3, K2SO4, KH2PO4, CSM+B (0.29 ppm 2X per week), ferrous gluconate (0.100 2X per week), and for my 2.0 dKH / 2.0 dGH water CaSO4 and MgSO4.
Have you tried DTPA chelated iron? It will remain available longer in your PH than the EDTA iron in CSM+B. The gluconate is good, but it goes away even faster. I had some issues similar to yours with S. Repens when CSM+B was my only iron source, but then I started dosing DTPA iron and ferrous gluconate. Combining that with an increase in MGSO4 really turned things around, even with my P at 5ppm. I read some old Tom Barr posts that recommended using all three forms of iron to get the best mix of availability, duration, and ease of uptake.
KZB likes this.

55 Gallon Planted / Pressurized CO2 / 2 Finnex Planted+ CC LEDs / Fluval 306 & 406 / Vecton UV / EI Ferts / Flourite Black
64D-1701 is offline  
post #9 of 12 (permalink) Old 02-12-2019, 10:41 PM
Wannabe Guru
 
PTrader: (0/0%)
Join Date: Feb 2017
Location: PA
Posts: 1,227
Fe gluc does bind faster to P than other chelators allow, but the Fe gluc is adsorbed by plant leaves much more rapidly than other chelates time-release aspect. Itís a race and I havenít seen any data that proves which form of chelate results in the most Fe++ uptake pound-for pound. Iíve been using only gluc form for about a year and see no downside to it, but I dose 6x / day.

The other aspect is that, regardless of binding, when the binding does occur it drops the bound P and Fe into the substrate where it is slowly consumed by the plants roots.
KZB and 64D-1701 like this.
Deanna is offline  
post #10 of 12 (permalink) Old 02-13-2019, 02:05 AM
Planted Tanker
 
burr740's Avatar
 
PTrader: (122/100%)
Join Date: Feb 2014
Location: Bama
Posts: 5,451
Roy have you ever tried dtpa instead of gluc? Might be worth a shot
Maryland Guppy, KZB and 64D-1701 like this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




burr740 is online now  
post #11 of 12 (permalink) Old 02-16-2019, 03:02 AM Thread Starter
Planted Tank Guru
 
Seattle_Aquarist's Avatar
 
PTrader: (64/100%)
Join Date: Jun 2008
Location: Seattle, WA
Posts: 6,291
Hi All,

Thank you for the suggestions, after this 'experiment' I may have to try something else.

Did a water change on the tank yesterday, after the water change the phosphates were down to 2.0 ppm. This week I will dose 1/2 the amount of phosphates keeping all other nutrients the same and see what happens; based upon Rotala Butterfly I am dosing a total of 1.3 ppm of PO4.

Based upon @burr740 suggestion I was doing some reading on the Barr Report about DTPA chelated iron. Apparently it can last longer in a tank however unlike ETDA chelates that break down rather quickly over time DTPA chelates can build up and bond with other metals. Possibly this is why some hobbyists dose all there ETDA, DTPA, and ferrous gluconate.

Roy_________
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

75 Gallon, 2X55W AH Supply CF 8800K, 1XFluval F&P 2.0; 45 Gallon Tall, 96Watt AH Supply CF 6700K; 30 Gallon Long; Fluval F&P 2.0; 20 Gallon, 1X26W AH Supply LED; all with CO2 and (Calcined) Montmorillonite Clay
Seattle_Aquarist is offline  
post #12 of 12 (permalink) Old 02-16-2019, 01:21 PM
Wannabe Guru
 
PTrader: (0/0%)
Join Date: Feb 2017
Location: PA
Posts: 1,227
Quote:
Originally Posted by Seattle_Aquarist View Post
Hi All,

Thank you for the suggestions, after this 'experiment' I may have to try something else.

Did a water change on the tank yesterday, after the water change the phosphates were down to 2.0 ppm. This week I will dose 1/2 the amount of phosphates keeping all other nutrients the same and see what happens; based upon Rotala Butterfly I am dosing a total of 1.3 ppm of PO4.

Based upon @burr740 suggestion I was doing some reading on the Barr Report about DTPA chelated iron. Apparently it can last longer in a tank however unlike ETDA chelates that break down rather quickly over time DTPA chelates can build up and bond with other metals. Possibly this is why some hobbyists dose all there ETDA, DTPA, and ferrous gluconate.
Both the EDTA and DTPA will bind to other metals once free of the original bonds and neither one is biodegradable, which is why there is so much concern from the likes of the EPA. The DTPA just holds metals longer at higher pH levels but, once the metal is removed, the chelate is in the tank to stay unless physically removed. In addition to w/c's, You can remove these chelates from the water column with activated carbon. Of course, if any metals happen to be bound to them, they will be removed as well. However, you could view it as a 'reset' activity whenever you become concerned about chelates being built-up too high.
Seattle_Aquarist and KZB like this.
Deanna is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Difficiency Identity. ryubui Plants 27 03-16-2015 09:17 AM
Phosphorus, KH, Iron and planting substrate question Codzilla General Planted Tank Discussion 2 12-25-2014 12:28 PM
how much iron??? wetworks Fertilizers and Water Parameters 5 09-19-2011 07:46 PM
Getting an Iron reading (any at all) scolley Fertilizers and Water Parameters 17 10-03-2004 09:21 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome